ThisNumber is an international directory of phone books and U.S. phone number lookup service.
Truecaller - Find a person by a name or phone number worldwide for free using Truecaller.
CallApp - Free Caller ID & Call Blocker app that allows mobile users to block phone calls, identify calls, blacklist unwanted callers and much more.
WhosCall - WhosCall is a reliable caller ID app whose popularity has led to its adoption by many users including international media. You can now manage the numbers calling you regardless of whether they are part of your contact list or not... read more.
CallerSmart - CallerSmart is an application that is basically used for the purpose of looking up mystery phone numbers for free.
NoPhoneSpam - Block calls from annoying or private numbers on your Android device. By bitfire.
Sync.ME - Search over 1 Billion phone numbers worldwide. Identify unknown phone numbers and block unwanted calls.